SYMPOSIA PAPER Published: 01 January 1992

Further Microstructural Characterization of Submerged-Arc Weld Metals


This paper presents the results of additional microstructural evaluations of Mn-Mo-Ni wire/Linde 80 flux submerged-arc weld metals typically found in Babcock & Wilcox fabricated reactor vessels. Optical metallography was performed on four Mn-Mo-Ni wire/Linde 80 surveillance weld metals to study the grain structure and to characterize the size and distribution of macroinclusions (>0.26 μm). These weld metals have a tempered bainitic structure with large amounts of manganese-rich inclusions.

Analytical TEM was used to characterize the carbides, coarse (0.1 to 2.0 μm) inclusions, and fine (2 to 50 nm) precipitates. Thin foil and extraction techniques were used to characterize particle morphology, while convergent beam diffraction and energy dispersive X-ray techniques were carried out to identify the crystal structural and chemical composition. The results are compared with previously evaluated Mn-Mo-Ni wire/Linde 80 flux submerged-arc weld metals. The data suggest that the initial Charpy impact properties may be related to the size and distribution of inclusions and not to their composition.

Author Information

Lawless, KR
University of Virginia, Charlottesville, VA
Lowe, AL
B&W Nuclear Service Co., Lynchburg, VA
Price: $25.00
Contact Sales
Reprints and Permissions
Reprints and copyright permissions can be requested through the
Copyright Clearance Center
Developed by Committee: E10
Pages: 186–199
DOI: 10.1520/STP17869S
ISBN-EB: 978-0-8031-5187-1
ISBN-13: 978-0-8031-1477-7